Hybrid Piezoelectric Capacitive Input Device for Accurate Haptic Feedback
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Solution Overview
Problem
Piezoelectric devices face challenges in static force measurements due to continuous electron leakage, leading to inaccurate user input detection, and capacitive sensors are sensitive to manufacturing variations requiring complex calibration.
Innovation Solution
An input device integrating both piezoelectric and capacitive sensors, where capacitive sensors correct for the leakage issues of piezoelectric devices, and piezoelectric devices calibrate capacitive sensors, providing accurate force measurements and haptic feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If piezoelectric devices are used for force measurement, then haptic feedback capability is provided, but measurement accuracy deteriorates due to continuous electron leakage
Solution Approach 1:
The patent combines piezoelectric devices and capacitive sensors into a hybrid sensing system. The piezoelectric devices provide haptic feedback capability through their actuator function, while capacitive sensors simultaneously measure applied force without suffering from electron leakage. The controller integrates signals from both sensor types to achieve accurate force measurement while maintaining haptic feedback functionality.
Solution Approach 2:
Capacitive sensors serve as an intermediary measurement mechanism that indirectly measures force through capacitance changes caused by distance variations between the touchpad surface and the user's input object. This intermediary approach avoids the direct electron leakage problem of piezoelectric devices while still providing force measurement capability.
2Stability of the object's composition
If capacitive sensors are used for force measurement, then static force measurement stability is improved, but device complexity increases due to manufacturing variations requiring calibration
Solution Approach 1:
The patent implements a feedback mechanism where the controller receives signals from both capacitive sensors and piezoelectric devices, compares them, and uses the piezoelectric device signals to correct calibration drift in the capacitive sensors. This feedback loop automatically compensates for manufacturing variations without requiring manual recalibration, reducing device complexity while maintaining measurement stability.
Solution Approach 2:
The system dynamically adjusts measurement parameters by switching between capacitive sensing and piezoelectric sensing based on the measurement conditions. For static measurements, capacitive sensors are used with their stable output, while for dynamic measurements requiring haptic feedback, piezoelectric devices are activated. This parameter switching approach optimizes performance while managing calibration complexity.
3Device complexity
If only piezoelectric devices are used, then device complexity is reduced, but reliability deteriorates due to inability to accurately determine proper response to user input
Solution Approach 1:
The patent segments the sensing function into two independent components: capacitive sensors for accurate force measurement and piezoelectric devices for haptic feedback generation. Each component performs its specialized function reliably, with the controller integrating both signals. This segmentation allows each sensor type to operate in its optimal performance range, improving overall reliability while managing complexity through functional division.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The combination of piezoelectric and capacitive sensors enhances the accuracy of user input detection and haptic feedback, overcoming the limitations of using either technology alone by compensating for leakage and calibration challenges.
Implementation Method 1
one or more piezoelectric devices configured to measure piezoelectric signals associated with user input on a sensing region
Implementation Method 2
a capacitive sensor configured to measure a distance between the capacitive sensor and the user input object
Data Source
AI summary
A method is provided. The method comprises obtaining, by a processing system and using a piezoelectric device, piezoelectric signals associated with user input on a sensing region of an input device; obtaining, by the processing system and using a corrective device, corrective signals associated with the user input on the sensing region of the input device; determining, by the processing system and based on the piezoelectric signals and the corrective signals, one or more events to be performed in response to the user input; and performing, by the processing system, the one or more events.